They're bracing for further assaults on the system.

Singapore's defence ministry said Tuesday that hackers had stolen the personal details of hundreds of staff and soldiers in what appeared to be a "targeted" cyber attack on its computer systems.

Officials said hackers had not collected any classified data earlier this month when they breached the ministry's "I-net system", which provides internet access to employees and young army conscripts undergoing national service, at dedicated computer terminals.

"The real purpose may have been to gain access to official secrets, but this was prevented by the physical separation of I-net from our internal systems," the ministry said in a statement, adding that it was probing the extent of the breach.

Hackers were able to steal the identity card details, telephone numbers and dates of birth of around 850 employees and people on military service.

The defence ministry said the attack "appeared to be targeted and carefully planned" and added it was braced for further assaults on the computer system.

Would be interesting to know if Mindef Malaysia has experienced anything similar since the assassination of Kim Jong-nam.